DE102018133049B4 - Side skirts for a motor vehicle - Google Patents

Abstract

Side skirts (9) for a motor vehicle, with a side skirt inner part (10) assigned to an underbody (1), with a bottom flange (13) and with a side skirt outer part (41), through which a cavity (36) of the side skirt (9 ) is limited, in which a reinforcement part (14) is arranged, which is fastened to the inner part of the side sill (10), the inner part of the side sill (10) and the lower chord (13) being designed as separate components, which extend along a direction of longitudinal extension the flange connection (31) running along the side skirt (9) are connected to one another at least indirectly, characterized in that: - the lower chord (13) and the reinforcement part (14) are designed as a preassemblable, construction variant-specific structural unit (15) and have a plurality of connecting elements (24) of the preassemblable structural unit (15) are connected to each other, - the connecting elements (24) are formed in two parts with respective joining areas (25, 26) along which n the height of the connecting elements (24) can be adjusted, and the respective connecting element (24) is formed from a fastening socket (21) for an energy store (37) of the motor vehicle and a support element.

Description

The invention relates to a side skirt for a motor vehicle according to the preamble of patent claim 1.

From the DE 10 2011 077 810 A1 a side sill for a passenger car is already known, which comprises a side sill inner part connected to an underbody, a bottom chord and a side sill outer part. The side sill inner part and the bottom chord are formed from a substantially L-shaped or C-shaped sheet metal component. The side sill outer part is also essentially L-shaped from a corresponding sheet metal component, with respective flange connections running in the longitudinal direction of the side sill at its lower, outer corner or in an upper, central area. The arrangement of the lower flange connection at the lower outer corner results in the advantage that the bottom flange of the side skirt can be pulled down relatively far, which leads to a corresponding enlargement of the cross section of the side skirt with the associated advantages under static and dynamic loads.

In the hollow space of the side sill, a reinforcement part with an approximately trapezoidal or hat-shaped cross section is provided, which is fastened to the inner part of the side sill.

The approximately L-shaped or C-shaped sheet metal component, which forms the side skirt inner part and the lower chord, is relatively complex to manufacture due to its large-format design and limits the selection of possible materials that can be used. To be more precise, some materials, such as high-strength steels, cannot be used without further ado for this sheet metal component, since there is a certain risk of cracking due to the high forming rate. Another problem is that such a large-format component can only be adapted with difficulty to different construction variants, which result in particular from varying drive concepts (vehicle with internal combustion engine, drive or electric drive). Also, construction variant-specific distinctions with regard to the derivatives within a model series, which result, for example, from the distinction between flatter designs for coupes or convertibles versus higher designs for sedans or SUVs and vans, can only be taken into account with such a large-format component with difficulty.

Since the sheet metal component according to the prior art, which forms the side skirts and the bottom flange, is also undercut in the vertical direction (z-direction) of the vehicle in the assembly direction, which runs parallel to the transverse direction of the vehicle (y-direction), this also results precisely during assembly respective mounting bushes for an energy store on the side skirts a relatively complicated installation, in which, for example, the reinforcement part must be cut out in the region of the respective mounting bushes and thus weakened.

Furthermore, the DE 10 2016 220 239 B3 a side skirt can be seen as known. the DE 10 2016 223 492 B3 discloses a body structure for a dual carriage vehicle. From the DE 10 2010 062 748 A1 a motor vehicle body is known. In addition, the DE 10 2015 203 309 A1 a vehicle body structure.

The object of the present invention is therefore to create a side skirt of the type mentioned above, by means of which an improved adaptability of the components to different construction variants of the side skirt can be realized with regard to simple production and assembly and a needs-based design.

According to the invention, this object is achieved by a side skirt with the features of claim 1 . Advantageous configurations are the subject matter of the respective dependent claims.

The side sill according to the invention, which comprises an inner part of the side sill assigned to an underbody, a lower chord and an outer part of the side sill, through which a cavity is delimited, in which a reinforcement part is arranged, which is attached to the inner part of the side sill, is characterized for achieving a simple Production and assembly as well as to achieve a favorable needs-based design characterized in that the side skirt inner part and the lower flange are designed as separate components, which are at least indirectly connected to one another along a flange connection running in the longitudinal direction of the side skirt. According to the invention, it is therefore provided that the previously one-piece component consisting of the side skirt inner part and the lower chord is now in two parts, and the two components along a flange connection running in the longitudinal direction of the side skirt, optionally with the intermediary of a further component such as the reinforcement part, at least indirectly with one another connect to. First of all, this has the advantage that the inner part of the side skirt and the bottom flange can be manufactured more easily and in a more needs-based manner. esp In particular, the risk of cracks forming in the area of the lower chord during its production, especially during its forming, is significantly reduced. In addition, different materials can be used for the inner part of the side skirt and the bottom chord in order to be adapted to the respective loads as required. For example, it is possible to use high-strength steel for the inner part of the side skirt, whereas more ductile materials can be used for the lower flange, for example.

A further advantage arises in particular when using the side sill in motor vehicles with different drive concepts, in particular in motor vehicles with a purely electric drive, a hybrid drive or a drive with an internal combustion engine. In the case of the side skirts according to the invention, the side skirt inner part can be produced across all construction variants and assigned to the underbody as a common part, with the lower chord being able to be easily adapted to the respective construction variant-specific requirements, which vary with the respective drive concepts. In particular, the fact that in vehicles with an underfloor energy store, due to its attachment, the side skirts in the area of the lower belt must be made significantly more complex than, for example, in a vehicle with an internal combustion engine, can be taken into account here.

For example, and in particular, it is possible when using the side skirts in a vehicle with an underfloor energy storage device to design the bottom flange as a preassemblable structural unit, specific to the construction variant, in order to facilitate production and assembly on the one hand and to achieve a needs-based design on the other hand, since this means, for example, in a row the assembly sequence or as a result of the joining direction, respective connecting elements of the side skirts can be designed with the energy storage device without an undercut, so that, for example, the reinforcement part does not have to be cut out. In addition, improved or simpler tolerance chains can also be achieved, since all relevant components are arranged on the side of the lower chord or the associated structural unit when an energy store is connected. By dividing said component into two parts, the inner part of the side skirt and the bottom flange, different vehicle heights, which result, for example, in sedans, off-road vehicles or vans on the one hand and flatter coupés, convertibles or the like on the other hand, can be taken into account in a more needs-based manner.

The bottom chord and the reinforcement part are designed as a pre-assembled, construction variant-specific structural unit. As a result, the side skirt inner part can be designed as part of the floor assembly in a simple manner across all construction variants, whereas the lower chord and the reinforcement part are specifically matched to a construction variant of the motor vehicle as parts of a preassembled unit. For example, a structural unit consisting of a lower flange and a reinforcement part for a vehicle with an underfloor energy storage device can be created, which is supplemented, for example, with corresponding connecting elements for connecting the energy storage device to the side skirts, whereas a structural unit for a motor vehicle with an internal combustion engine can be created, which is simplified in comparison is trained. In this way, the side skirts can easily be matched overall to a particular design variant of the motor vehicle, with the particular design variants relating in particular to the drive concept, but possibly also to the vehicle height of the vehicle (sedans, off-road vehicles, vans, coupes, convertibles, etc.) .

The bottom chord and the reinforcement part are connected to one another via a number of connecting elements of the preassembled structural unit. Thus, the reinforcement part and the bottom flange can not only be preassembled, but are also connected to one another in a correspondingly stable and rigid manner, so that considerable forces, for example static and dynamic bending and/or torsional forces, which act on the side skirts, can be absorbed by the structural unit.

The respective connecting elements are formed in two parts with respective joining areas along which the length of the connecting elements can be adjusted. Due to the two-part design of the connecting elements, in particular the adjustability in the vertical direction of the vehicle (z-direction) is achieved, so that a particularly good adaptability of the connecting elements can be achieved.

The respective connecting elements are formed from a fastening socket for an energy store of the motor vehicle and from a support element, in particular a partition plate, which can be displaced or adjusted relative to one another at least in the vertical direction of the vehicle (z-direction) and then, for example, by spot welding, laser welding or another joining method, optionally also a mechanical connection method, can be connected to one another. Due to the adjustability of the connecting elements, the mounting sockets on which the underfloor energy storage device can be attached is fastened, can be connected in a simple manner via the associated support elements, in particular the bulkhead plates, over a considerable height extension direction and in particular to the associated reinforcement part of the side skirt. In this case, tolerances can be compensated for in a particularly simple manner by the adjustability of the connection between the respective connecting element and the associated support element.

In a further preferred embodiment of the invention, it is provided that the lower chord has a reference element, in particular a plug-in opening, for aligning an energy store. According to the invention, therefore, all components required for aligning the energy store relative to the side sill, namely both the staking opening or similar reference element and the connecting elements for fixing the energy store to the associated side sill, are thus arranged on the side of the lower chord. This enables the tolerance chains to be reduced in an optimal manner.

A further advantageous embodiment of the invention provides that the side sill inner part is designed as a common part that covers all construction variants. This results on the one hand in a particularly simple manufacture of the inner part of the side sill itself, but also in a simple design of the underbody to which the inner part of the side sill covering all structural variants is fastened.

In addition, it has proven to be advantageous if the inner part of the side sill and the lower chord are connected to one another through the intermediary of the reinforcement part. The lower chord and the reinforcement part can thus be connected to one another during the preassembly of the structural unit, with the reinforcement part then serving to connect the lower chord indirectly to the side sill inner part when the structural unit is connected to the inner part of the side sill.

A further advantageous embodiment of the invention provides that the side sill inner part and the bottom chord are made of different materials, the side sill inner part being made in particular of a high-strength or ultra-high-strength steel and the bottom chord being made of a comparatively more ductile material. In this way, account can be taken in particular of the fact that both parts are exposed to different static and dynamic loads and manufacturing requirements.

In this context, it has proven to be advantageous in a further embodiment of the invention if the inner part of the side skirt is formed from a galvanized component that is press-hardened in direct hot forming. This is possible because the inner part of the side sill is formed separately from the lower chord and consequently has a simpler geometric shape, which allows such a method. In contrast to other, similar methods, it is possible in particular to dispense with forming and final trimming, whereas hot trimming takes place during hot forming and hardening, as well as final trimming by lasering. The process described, in which the inner part of the side skirt is press-hardened in direct hot forming, has the advantage of a load-oriented design of the component, a high degree of material utilization and a more economical production compared to conventional processes.

The advantages mentioned above in connection with the side sill according to the invention apply in the same way to a modular system. This modular system is characterized in particular by the use of a cross-variant side skirt inner part, which is assigned to the floor pan, and a number of variant-specific lower belts, which are particularly tailored to the respective drive concept of the vehicle. In this way, account can be taken in particular of the fact that, for example, a purely electrically operated vehicle with a correspondingly large underfloor energy storage device requires corresponding connection points on the lower flange, which are not required in other vehicle variants, for example vehicles operated purely with fuel. In this respect, the division of the side sill in this area into the side sill inner part covering all construction variants and the plurality of construction variant-specific lower chords has the advantage that the lower chord can be specifically adapted in a particularly advantageous manner.

In this case, the construction-variant-specific bottom chord is preferably part of a construction-variant-specific structural unit, which also includes the reinforcement part, which is accommodated in the cavity of the side sill. It should be taken into account here that the reinforcement part can also be designed specifically for the construction variant and/or connected to the lower flange in order to achieve ideal adaptation to the respective construction variant of the motor vehicle. In this case, the respective structural variant-specific structural unit can be preassembled in a simple manner and fed to the manufacturing process, for example as part of the production of the body shell of the respective motor vehicle.

An advantage of the connection of the lower chord with the reinforcement part can be realized in a further embodiment in that this construction parts can be pre-assembled via several connecting elements to form a construction variant-specific unit. These connecting elements can be, for example, respective fastening sockets for an energy store of the motor vehicle and respectively associated support elements, in particular bulkhead plates, which can be joined together at respective joining areas along which the length of the connecting elements can be adjusted. The great advantage of such a construction variant-specific structural unit can be seen in particular in the fact that the lower flange and associated reinforcement part can be joined without the reinforcement part in particular having to be cut out in the area of the respective connecting elements. This would be the case if the reinforcement part were designed separately from the connecting elements and then fastened to the inner part of the side sill in the transverse direction of the vehicle (y-direction). If the inner part of the side sill and the bottom chord are designed in one piece as an L-shaped sheet metal component, subsequent assembly of the reinforcement part on the inner part of the side sill can only be carried out if there are respective reinforcement parts between the lower chord and the reinforcement part by cutting out the reinforcement part accordingly in the area of the connecting elements , since otherwise a joint in the transverse direction of the vehicle (y-direction) can no longer take place.

The advantages mentioned above in connection with the side sill according to the invention and the modular system also apply to a method for producing such a side sill.

Further features of the invention result from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own.

• 1 eine ausschnittsweise Perspektivansicht auf eine Karosserie eines Personenkraftwagens im Bereich eines teilweise dargestellten erfindungsgemäßen Seitenschwellers, welcher ein einer Bodengruppe zugeordnetes Seitenschweller-Innenteil sowie ein als vormontierbare bauvariantenspezifische Baueinheit mit einem Untergurt und einem Verstärkungsteil umfasst, welche bei der vorliegenden bauvariantenspezifischen Ausführungsform über eine Mehrzahl von Verbindungselementen miteinander verbunden sind, welche jeweilige Befestigungsbuchsen zur Befestigung eines Energiespeichers des Kraftwagens und zugeordnete Schottbleche umfassen, welche in Fahrzeughochrichtung in ihrer Relativlage zueinander einstellbar und miteinander verbindbar sind,
• 2a in jeweiligen Perspektivdarstellungen die schematische Erläuterung eines ersten Fertigungsschritts zur Herstellung der vormontierbaren Baueinheit gemäß 1, in welchem jeweilige Schottbleche mit dem Verstärkungsteil verbunden werden,
• 2b in jeweiligen Perspektivdarstellungen die schematische Erläuterung eines weiteren Verfahrensschritts zur Herstellung der vormontierbaren Baueinheit gemäß 1, in welchem zur Befestigung eines Unterflur-Energiespeichers an dem Kraftwagen jeweilige Befestigungsbuchsen vorgesehen sind, welche oberseitig des Untergurts der vormontierbaren Baueinheit befestigt werden,
• 2c jeweilige weitere Perspektivansichten des Verstärkungsteils mit den Schottblechen gemäß 2a und dem Untergurt mit den Befestigungsbuchsen gemäß 2b, welche in einem weiteren Verfahrensschritt zu der fertigen vormontierbaren Baueinheit miteinander verbunden werden,
• 3 eine perspektivische Explosionsdarstellung des Zusammenbaus der vorgefertigten, bauvariantenspezifischen Baueinheit mit einem mittleren Seitenwandteil, welcher anschließend mit dem auf Seiten der Bodengruppe angeordneten Seitenschweller-Innenteil verbunden wird,
• 4 eine ausschnittsweise Perspektivansicht des Zusammenbaus der vorgefertigten, bauvariantenspezifischen Baueinheit mit dem auf Seiten der Bodengruppe fest angeordneten Seitenschweller-Innenteil, welches mit dem Untergurt der Baueinheit entlang einer in Längserstreckungsrichtung des Seitenschwellers verlaufenden Flanschverbindung unter Vermittlung des Verstärkungsteils mittelbar miteinander verbunden ist,
• 5 eine perspektivische und gegenüber 4 stark vergrößerte Schnittansicht des teilweise dargestellten Seitenschwellers, wobei außerdem unterseitig des Seitenschwellers ein Unterflur-Energiespeicher für einen elektrischen Antrieb des Kraftwagens befestigt ist,
• 6 eine Perspektivansicht eines der aus der jeweiligen Befestigungsbuchse und dem zugeordneten Schottblech gebildeten, zweiteiligen Verbindungselements, über welches der Untergurt und das Verstärkungsteil miteinander verbunden sind,
• 7 eine ausschnittsweise Schnittansicht durch den Seitenschweller gemäß den 1 bis 5 mit dem daran befestigten Unterflur-Energiespeicher,
• 8 eine perspektivische Explosionsdarstellung der vormontierten Baueinheit gemäß einer weiteren Ausführungsform, bei welcher die jeweiligen Verbindungselemente zunächst in ihrer Höhe eingestellt und verbunden werden sowie mit dem Verstärkungsteil verbunden werden, bevor sie mit dem Untergurt verbunden werden,
• 9 eine perspektivische Schnittansicht des Seitenschwellers analog zu 5 in einer alternativen Ausführungsform, bei der die jeweilige Befestigungsbuchse des Energiespeichers einen unteren Wandbereich des Verstärkungsteils durchragt und mit einem zugeordneten Schottblech verbunden ist, welches seinerseits innerhalb des durch das Verstärkungsteil und das Seitenschweller-Innenteil begrenzten Hohlraum angeordnet ist, und in
• 10 eine Perspektivansicht auf eine weitere, alternative Ausgestaltung des Seitenschwellers, bei welchem eine andersartige, vormontierbare, bauvariantenspezifische Baueinheit vorgesehen ist, welche bei einem rein mit Kraftstoff betriebenen Personenkraftwagen zum Einsatz kommt, und bei welcher der Untergurt und das Verstärkungsteil lediglich über ein Verbindungselement miteinander verbunden sind.

The invention will now be explained in more detail using a preferred exemplary embodiment and with reference to the drawings. Show it:

• 1 a fragmentary perspective view of a body of a passenger car in the area of a partially shown side skirt according to the invention, which includes a side skirt inner part assigned to an underbody and a construction variant-specific structural unit with a lower chord and a reinforcement part that can be preassembled and which, in the present construction variant-specific embodiment, has a plurality of connecting elements with each other are connected, which comprise respective fastening sockets for fastening an energy storage device of the motor vehicle and associated bulkhead plates, which can be adjusted in their relative position to one another in the vertical direction of the vehicle and can be connected to one another,
• 2a in respective perspective views, the schematic explanation of a first manufacturing step for the production of the pre-assembled unit according to 1 , in which respective bulkhead plates are connected to the reinforcement part,
• 2 B in respective perspective representations, the schematic explanation of a further method step for the production of the pre-assembled unit according to 1 , in which respective fastening sockets are provided for fastening an underfloor energy store to the motor vehicle, which are fastened on top of the lower flange of the pre-assemblable unit,
• 2c respective further perspective views of the reinforcement part with the bulkhead plates according to 2a and the bottom chord with the fastening sockets 2 B , which are connected to each other in a further process step to form the finished pre-assembled unit,
• 3 a perspective exploded view of the assembly of the prefabricated, construction variant-specific structural unit with a middle side wall part, which is then connected to the side skirts inner part arranged on the side of the floor pan,
• 4 a sectional perspective view of the assembly of the prefabricated, construction variant-specific assembly with the side skirt inner part fixed on the side of the underbody, which is indirectly connected to the lower flange of the assembly along a flange connection running in the longitudinal direction of the side skirt through the intermediary of the reinforcement part,
• 5 a perspective and opposite 4 greatly enlarged sectional view of the partially shown side sill, with an underfloor energy store for an electric drive of the motor vehicle also being attached under the side sill,
• 6 a perspective view of one of the two-piece formed from the respective mounting socket and the associated partition plate Connecting element, via which the lower chord and the reinforcement part are connected to one another,
• 7 a partial sectional view through the side skirts according to 1 until 5 with the attached underfloor energy storage device,
• 8th a perspective exploded view of the preassembled assembly according to a further embodiment, in which the respective connecting elements are first adjusted in their height and connected and are connected to the reinforcement part before they are connected to the lower chord,
• 9 a perspective sectional view of the side skirt analogous to 5 in an alternative embodiment, in which the respective fastening bushing of the energy store protrudes through a lower wall area of the reinforcement part and is connected to an associated partition plate, which in turn is arranged within the cavity delimited by the reinforcement part and the inner part of the side sill, and in
• 10 a perspective view of a further, alternative embodiment of the side sill, in which a different, pre-assemblable, construction variant-specific unit is provided, which is used in a purely fuel-powered passenger car, and in which the lower chord and the reinforcement part are only connected to one another via a connecting element .

1 shows a fragmentary perspective view of a body of a passenger car, of which in particular an underbody 1 can be seen, on the outside of which a side wall 2 extending in the longitudinal direction of the vehicle (x-direction) or in the vertical direction of the vehicle (z-direction) is arranged, of which only an inner side wall part 3 can be seen. A central and an outer side wall part adjoin this inner side wall part 3 on the outside. A front and a rear door opening 4, 5 can be seen in the side wall 2 or the side wall part 3, as can door pillars in the form of an A pillar 6, a B pillar 7 and a C pillar 8.

On the left-hand side of the vehicle—viewed in the forward direction of travel—a side sill 9 can be seen in part, which extends at least essentially between a front wheel arch 11 and a rear wheel arch 12 . The side sill 9 comprises a side sill inner part 10 which extends at least essentially from the front wheel arch 11 to the rear wheel arch 12 and which is fastened to the underbody 1 or the inner side wall part 3 of the side wall 2 in the present case.

In addition, the side sill 9 comprises a bottom chord 13, which delimits it downwards in the vertical direction of the vehicle (z-direction) and extends approximately horizontally in the transverse direction of the vehicle (y-direction) and in the longitudinal direction of the vehicle (x-direction), as well as a reinforcement part 14 with an approximately hat-shaped cross section, which is accommodated in a cavity formed by the side skirts 9 in a manner described in more detail below. The lower chord 13 is formed separately from the side sill inner part 10 in a manner described in more detail below and is connected to the side sill inner part 10 along a flange connection running in the longitudinal direction of the side sill 9 through the intermediary of the reinforcement part 14 . In addition, the bottom chord 13 and the reinforcing member 14 form a with reference to FIG 2a until 2c explained in more detail pre-assembled and construction variant-specific structural unit 15, which is first produced separately from the floor assembly 1 and then attached to the floor assembly 1 or to the side skirt inner part 10.

Based on 2a until 2c The assembly of the preassemblable, construction variant-specific structural unit 15 will now be explained below:

2a shows the reinforcement part 14 and the respective bulkhead plates 16, 17 in a respective perspective view, which - as shown in 2a is indicated - for example by spot welding, laser welding or a similar joining method, optionally also by means of a mechanical connection, with the reinforcement part 14 are connected. The partition plates 16 are arranged distributed over the direction of longitudinal extension on the reinforcement part 14, namely in a corner area between a vertically running wall area 19 and a substantially horizontally extending wall area 20. The partition plates 17 form a respective front and rear end of the side skirt 9, if necessary can also be attached to jacking points, particularly in the front and rear areas of the side skirts 9 . The reinforcement part 14 is produced, for example, by roll forming.

2 B shows in respective perspective representations the schematic explanation of a further method step for the production of the pre-assembled structural unit according to FIG 1 , In which for the attachment of an underfloor energy store on the motor vehicle respective attachment sockets 21 before are seen, which are fixed on the top side of the lower flange 13 of the preassembled unit 15, for example by spot welding. The fastening bushings 21 are produced here by cold extrusion and comprise a head 22 and a shaft 23 connected to it in one piece. In the respective fastening bushing 21 there is a threaded hole 39 ( 7 ) introduced, in which a screw 38 ( 7 ) for fastening the energy store 37 ( 7 ) can be fixed. This threaded hole 39 is arranged in register with an opening inside the bottom chord 13 .

2c shows respective further perspective views of the reinforcement part 14 with the bulkhead plates 16, 17 according to FIG 2a and the lower chord 13 with the fastening sockets 21 according to FIG 2 B , which are connected to one another in a further process step to form the finished preassembled structural unit. The bulkhead plates 16 on the side of the reinforcement part 14 and the associated fastening bushings 21 on the side of the lower chord 13 are connected to one another by spot welding, optionally also by another joining method. Each pair - consisting of the corresponding bulkhead plate 16 and the associated mounting bushing 21 - forms a connecting element 24, via which the reinforcement part 14 and the lower chord 13 are connected to one another. Accordingly, the lower chord 13 and the reinforcement part 14 are connected to one another via a plurality of connecting elements 24 of the structural unit 15 which can be preassembled.

In synopsis with 6 , which shows a perspective view of one of the two-part connecting element 24 formed from the respective fastening sleeve 21 and the associated bulkhead plate 16, via which the lower flange 13 and the reinforcing part 14 are connected to one another, it can be seen that both the respective bulkhead plate 16 and the associated fastening sleeve 21 each have a joining area 25, 26, which has a surface that extends vertically in the vertical direction of the vehicle (z-direction) and in the transverse direction of the vehicle (y-direction) or is designed as such. Along these surfaces or joining areas 25, 26, the respective partition plates 16 and the associated fastening bushings 21 can be adjusted in their relative position relative to one another, in particular in the vertical direction of the vehicle (z-direction), but also in the transverse direction of the vehicle (y-direction). After this setting, the bulkhead plate 16 and the associated fastening bushing 21 are then joined, for example by spot welding. These process steps are all carried out as part of the pre-assembly of the structural unit 15.

In addition, the lower chord 13 and the reinforcement part 14 are also connected directly to one another, namely along a flange connection 27 running in the longitudinal direction of the side sill. The respective flanges are connected by laser welding, although other joining methods are also conceivable.

Based on the perspective exploded view of 3 , above, it can be seen that the side skirt inner part 10 is welded to the floor assembly 1 as part of the body shell production. According to the illustration in 3 , below, the prefabricated, construction variant-specific structural unit 15 is first connected to a side frame - middle 42 according to arrow 43, after which the side frame - middle 42 is connected on the inside to a side frame - not shown here - inside and a side frame - also not shown - outside. Side frame - center 42, side frame - inside and side frame - outside, which can each be designed in one or more parts, thus form the side frame or the side wall of the body. In the area of the side skirt 9, the outside of the side frame forms the in 7 recognizable side skirt outer part 41.

Following this, the side frame with the structural unit 15 is fastened to the underbody 1 with the side skirt inner part 10 .

4 shows a detail perspective view of the assembly of the prefabricated, construction variant-specific structural unit 15 with the side sill inner part 10 fixedly arranged on the side of the floor pan 1 again separately.

In synopsis with 5 , showing a perspective and opposite 4 greatly enlarged sectional view of the partially shown side sill 9 shows, or in conjunction with 7 , which shows a sectional view from the front of the complete side sill 9, it can be seen in particular that the lower chord 13 is connected indirectly to the side sill inner part 10 via the reinforcement part 14. This indirect connection between the bottom chord 13 and side skirts inner part 10 takes place in particular on a in the 5 and 7 recognizable lower flange 28 of the cross-sectionally hat-shaped reinforcement part 14, which connects an upwardly angled flange 29 of the lower chord 13 to a lower end region or flange 30 of the inner part 10 of the side skirt. The connection between the flange 28 of the reinforcement part 14 and the flange 29 of the lower chord 13 forms the flange connection 27 described above, which is produced during the pre-assembly of the structural unit 15 .

Spot welding during body-in-white production turns flange 28 of reinforcement part 14 with flange 30 of side skirt inner part 10 into a flange connection that runs in the longitudinal direction of side skirt 9, i.e. at least essentially horizontally and in the longitudinal direction of the vehicle (x-direction). 31 is connected and the indirect connection between the lower flange 13 and the inner part 10 of the side skirt is thereby established. On the other hand, in the upper area, an upper flange 33 of the reinforcement part 14 is connected to the side skirt inner part 10 along a flange connection 32 that also runs horizontally and in the longitudinal direction of the vehicle (x-direction).

In 7 the side sill outer part 41 can also be seen, which is connected with an upper flange 45 to a flange 34 of the side sill inner part 10 . In a lower outer area of the side sill 9 , the side sill outer part 41 is connected to a flange 35 of the lower chord 13 via a flange 46 . Accordingly, the side sill outer part 41, together with the side sill inner part 10 and the lower chord 13, delimits the cavity 36 of the side sill 9, within which, among other things, the reinforcement part 14 and the connecting elements 24 between the reinforcement part 14 and the lower chord 13 are arranged.

In synopsis of 6 and 7 It is also clear how the height extension in the vehicle vertical direction (z-direction) of the respective connecting elements 24 is adjusted. The respective joining areas 25, 26 of the respective partition plate 16 and the associated fastening bushing 21 can be seen, which lie flat against one another and along which vertical in the vehicle vertical direction (z-direction) and in the vehicle transverse direction (y-direction) an adjustment of the partition plates 16 and the associated Fastening sockets 21 in their position relative to each other is possible. However, this process step takes place as part of the pre-assembly of structural unit 15.

In addition, from the 5 and 7 still clearly recognizable in which way the underfloor energy store 37 is fastened to the respective side sill 9 for an electric drive of the motor vehicle. This takes place via respective screws 38 which are screwed into the respective associated threaded hole 39 of the corresponding fastening bushing 21 .

In order to achieve a precisely positioned arrangement of the underfloor energy store 37 relative to the side sill 9, a lower flange 13 is in the 2 B and 2c recognizable reference element, in particular a plug-in opening 40, is provided for aligning the energy store 37. Accordingly, this plug-in opening 40 is already provided during the preassembly of the structural unit 15, so that the connecting elements 24 can be aligned with it in order to keep corresponding tolerance chains particularly low.

The side sill inner part 10 and the bottom chord 13 are made from different materials, with the side sill inner part 10 being made in particular from a high-strength or ultra-high-strength steel and the bottom chord 13 being made from a steel material that is more ductile in comparison. The side sill inner part 10 can also be made from a galvanized component that is press-hardened in direct hot forming.

8th shows a perspective exploded view of the preassembled structural unit 15 according to a further embodiment, in which the respective connecting elements 24 - comprising the respective fastening bushing 21 and the associated bulkhead plate 16 - are first adjusted in terms of their height and connected to one another and connected to the reinforcing part 14 before they are Can also be connected to the bottom chord 13. In other words, the fastening bushings 21 and the associated bulkhead plate 16 are mutually aligned and joined to one another at the desired height/position and are also connected to the reinforcement part 14 . The sequence of the process steps can vary if necessary. It is conceivable first to fasten the respective fastening bushings 21 to the reinforcement part 14 and then to align and fasten the associated bulkhead plates 16 to the respective fastening bushes, or to first align the fastening bushes 21 and the associated bulkhead plate 16 with one another and to connect them to one another, and then carry out the attachment of the connecting elements 24 created in this way to the reinforcement part.

However, it is essential for the present embodiment of the structural unit 15 that the lower flange is only connected to the reinforcement part 14 (via the flange connection 27) or the connecting elements 24 after the method steps described above.

In 8th 12 is a sectional perspective view of the side sill 9 analogous to FIG 5 shown in an alternative embodiment, in which the respective mounting bushing 21 of the energy storage device 37 extends through the lower wall region 20 of the reinforcement part 14 and is connected to an associated bulkhead plate 16, which is its is arranged on the one hand within the cavity 47 bounded by the reinforcement part 14 and the inner part 10 of the side sill. In the present case, too, the respective partition plate 16 and the associated fastening bushing 21 each have a joining area 25, 26, which has a surface that extends vertically in the vehicle vertical direction (z-direction) and in the vehicle transverse direction (y-direction) or is designed as such . Along these surfaces or joining areas 25, 26, the respective partition plates 16 and the associated fastening bushings 21 can be adjusted in their relative position relative to one another, in particular in the vertical direction of the vehicle (z-direction), but also in the transverse direction of the vehicle (y-direction). After this setting, the bulkhead plate 16 and the associated fastening bushing 21 are then joined, for example by spot welding.

In the present case, these process steps can also be carried out during the pre-assembly of the structural unit 15 . In this case, the lower chord 13 is again formed separately from the reinforcement part 14 and is connected to it via the flange connection 27 . In the present case, the lower chord 13 is also formed separately from the inner part 10 of the side sill and is connected to it via the flange connection 31 through the intermediary of the reinforcement part 14 .

Finally shows 10 an alternative embodiment of the side skirt 9, in which a different, pre-assembled, construction variant-specific structural unit 15 is provided, which is used in a purely fuel-powered passenger car. Since no connecting elements 24 are required for connecting the energy store 37, all partition plates 16 and fastening bushings 21 have been omitted except for a rear pair, so that the lower chord 13 and the reinforcement part 14 are only connected to one another via this one connecting element 24. However, the flange connections between the lower flange 13 and the reinforcement part 14 (as part of the pre-assembly of the structural unit 15) and between the structural unit 15 and the side skirt inner part 10 are essentially identical to the previously described embodiments.

Overall, a modular system can thus be seen in which the lower flange 13 or the structural unit 15 can be adapted and preassembled in a simple manner specific to the construction variant - here depending on the drive type of the motor vehicle - and then connected to the cross-construction side skirt inner part 10 in order to achieve the desired to achieve simple, cost-effective and needs-based variance in the construction methods between the different vehicle configurations.

Claims (7)

Side skirts (9) for a motor vehicle, with a side skirt inner part (10) assigned to an underbody (1), with a bottom flange (13) and with a side skirt outer part (41), through which a cavity (36) of the side skirt (9 ) is limited, in which a reinforcement part (14) is arranged, which is fastened to the inner part of the side sill (10), the inner part of the side sill (10) and the lower chord (13) being designed as separate components, which extend along a direction of longitudinal extension the flange connection (31) running along the side sill (9) are connected to one another at least indirectly, characterized in that: - the lower chord (13) and the reinforcement part (14) are designed as a preassemblable, construction variant-specific structural unit (15) and have a number of connecting elements (24) of the preassemblable Unit (15) are connected to each other, - the connecting elements (24) are formed in two parts with respective joining areas (25, 26), along we lchen the connecting elements (24) are adjustable in their height, and - the respective connecting element (24) is formed from a fastening socket (21) for an energy store (37) of the motor vehicle and a support element. Side skirts (9) after claim 1 , characterized in that the supporting element is a partition plate (16). Side skirts (9) after claim 1 or 2 , characterized in that the lower chord (13) has a reference element for aligning an energy store (37). Side sill (9) according to one of the preceding claims, characterized in that the side sill inner part (10) is designed as a common part covering all construction variants. Side sill (9) according to one of the preceding claims, characterized in that the side sill inner part (10) and the lower chord (13) are indirectly connected to one another via the reinforcement part (14). Side sill (9) according to one of the preceding claims, characterized in that the side sill inner part (10) and the lower chord (13) are formed from different materials. Side sill (9) according to one of the preceding claims, characterized in that the side sill inner part (10) is formed from a galvanized component which is press-hardened in direct hot forming.

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